This invention relates to a phase separator. More particularly, this invention relates to a motion-insensitive phase separator for use in marine applications.
Phase separators are used in the oil industry to separate oil and gas from water in a multi-phase production fluid from a well bore. Most oil deposits occur in combination with water and gas. Frequently, because of the high geologic pressures involved, the oil is more or less homogeneously mixed in with the water, and the gas is dissolved in the mixture. Phase separators serve to separate out the three phases so that the oil and gas can be further processed.
Where drilling for oil and gas is undertaken over an ocean or other body of water, the phase separators are frequently located on a vessel maintained in position at sea. One problem arising in these installations is that the motion of the vessel and consequently of the phase separator causes the incoming fluid mixture to slosh about within the separator, thereby generating foam and impeding the separation process.
Separators which are used at sea are generally provided with structure for combating the effects of wave induced motion. As illustrated in FIG. 1, one such prior art phase separator includes a tank 12 having a single, centrally located, inlet 14. A packed box distributor 16 is disposed at the inlet 14 for spreading out the incoming fluid mixture throughout the tank 12. Tank 12 is provided with a pair of spaced gas outlets 18 and 20, a centrally located water outlet 22 and a centrally located oil outlet 24. A liquid containing chamber 26 is defined inside tank 12 by a separator plate 28 and a pair of partitions 30 and 32 in which respective flapper valves 34 and 36 are located. Water outlet 22 and oil outlet 24 communicate with chamber 26. Water outlet 22 is located at a bottom of tank 12, below a water level or water-oil interface 38, while oil outlet 24 is located between water level 38 and an oil level or oil-gas interface 40. Also located inside chamber 26 are separation media in the form of a plurality of packing structures 42 which serve to separate the oil and the water components from one another.
FIG. 2 depicts another separator designed specifically for marine applications. An elongate tank 44 is provided at one end with an inlet 46 for delivering a fluid mixture to tank 44. At an opposite end of tank 44 are provided a gas outlet 48, a water outlet 50 and an oil outlet 52. A cyclonic preseparator inlet device 54 is located at inlet 46, while a plurality of packing structures or perforated plates 56 are disposed at the bottom of tank 44 between inlet 46 and outlets 48, 50, and 52. Water outlet 50 is located at a bottom of tank 44, below a water level or water-oil interface 58, while oil outlet 52 is located between water level 58 and an oil level or oil-gas interface 60.